I don’t! If you have a question, something that needs figuring out, just poll the people who are using your software, there’s no good reason telemetry, and especially not if it’s not opt-in.
If you really need to make sure everyone sees it, you could even have a little news addon like in Manjaro so everyone sees the link to the poll.
Anyway, would this only apply to the default flavour, am I safe with my KDE spin?
EDIT: apparently it’s GNOME only, just saw the answer above, and hopefully the KDE spin team will provide sane defaults = no telemetry. Thanks @glitch9138